This application makes reference to, incorporates the same herein, and claims all benefits accruing under 35 U.S.C. xc2xa7119 from my application ROTOR HAVING PRINTED WIRING COMMUTATOR MEMBER AND FLAT MOTOR HAVING THE ROTOR filed with the Japanese Patent Office on the 19th day of June 2000 and there duly assigned Serial No. 182521/2000.
1. Field of the Invention
The present invention relates to a rotor, which has a printed wiring commutator member, used for audio apparatus such as a mini-disc player or an alarm in mobile communications apparatus, and more particularly, to a rotor having a printed wiring commutator member that does not require through hole plating so that production cost can be reduced, and to a flat motor incorporating the rotor.
2. Description of the Related Art
In a conventional printed wiring commutator for a flat coreless motor, six segment patterns are separated by slits on the front side of a printed wiring board. Simultaneously, opposite segments of the six segments are electrically connected on the rear side of the printed wiring board by through hole plating and a plurality of air-core coils are further arranged on the rear side of the printed wiring board. The printed wiring commutator member is integrally formed of resin.
Printed wiring commutators that have patterns formed on both sides of a printed circuit board coupled via through holes are widely used since the design of the commutator member is very easy. Additional work however, such as punching the printed wiring board, processing the through holes with a process such as a copper plating process, or resist processing for insulation when the coil is arranged, is required and production cost is increased correspondingly.
Accordingly, it is an object of the present invention to provide an improved rotor.
It is another object to provide a rotor bearing a plurality of segments of a pattern formed on a printed wiring commutator member that are electrically coupled together without plated through holes.
It is still another object to a rotor bearing a plurality of electrically connected segments of a pattern that is amenable to lower production costs.
To achieve these and other objects, there is provided a rotor having a printed wiring commutator formed on a printed wiring board that has a shaft installation hole located at the center of a printed wiring board. At least six segment patterns electrically separated by slits are formed around the shaft installation hole, and simultaneously, at least three electrical conductors connect every two segment patterns. Terminal connection patterns are arranged at the outer circumference of the printed wiring board, and a printed wiring commutator member is formed, not by through hole plating, to provide at least three of the electrical conductors in order to connect pairs of the segmented patterns. A plurality of air-core armature coils are installed on the side of the wiring board opposite to the segmented patterns, and terminals of the air-core armature coils are connected to the terminal connection patterns through notches disposed along the outer circumference.
It is preferred in embodiments of the present invention that at least one of the three electrical conductors be formed as a terminal of the air-core armature coil.
Also, it is preferred that part of a spark quenching printed resistor be located at part of the conductive body configured as the terminal to cover the conductive body.
Additionally, it is preferred that a plurality of resin passing holes be installed at the outer circumference of any array of the segmented patterns.
A flat motor having a rotor with this structure and a printed wiring commutator is provided wherein vibrations are generated during rotation by constructing the rotor to be non-circular and the motor to be formed of a magnet disposed to face the rotor via an axial gap and a housing accommodates the rotor and magnet, or alternatively a flat motor is constructed to use this rotor with a printed wiring commutator wherein the rotor is formed to be circular and the motor is formed of a magnet disposed to face the rotor via an axial gap, and a housing accommodates the rotor and magnet. It is preferred that the position of the patterns that form the terminal connection pattern on the rotor be located more radially outward than the outer circumference of the magnet.